well I am not sure what you are asking but I will answer both ways.
option 1:No you can not play all ORIGINAL halo maps, but you can download them from file share.
option 2: yes you can play all maps from the start of the game!
Bungie and 343i have approved 23 maps for use in online multiplayer in Halo: Reach.
No. Anniversary only comes with the six new matchmaking maps and the new firefight map. You only have access to those maps on the Anniversary disc. The only way to play both the Reach maps and the Anniversary maps is to buy the map pack for Anniversary or buy the game and use the code inside the case to upload the Anniversary maps to your hard drive for your Reach disc to access.
No because they have made new maps and it's an entire new game, also it's before the first halo we have ever played.
Yes
Refering to halo 3 and halo reach their is a custom forge game mode, here you can build and shape your very own map creations for both custom and recreational use.
In halo reach,You can not use cheat codes.nor in any halo game
yes ,because halo reach is the last halo game,therefore,it would have to be used
No.
You can't get Halo on PC
You can in HALO 1 if you use mods, but it has to be on the computer.
i dont understand what ur saying im able to use all my forge creations maybe u just have to choose a different game type variant.
use tthe action sack playlist.
No, this is only a feature for Halo : Reach